The present invention concerns a dust separator for the separation of even fine dusts from flowing gaseous media.
Dust separators for gaseous media are especially important at places where a destruction of vital components can result, such as, for example, in coal dust-fired gas turbines, coal gasification plants, firings by means of fluidized bed combustion, etc.
For example, it is possible in coal gas-fired gas turbines that poor dust separation can result in the turbine blades of the first stages being destroyed by erosion even after only a few days of continuous operation.
For these reasons and also with respect to achieving as complete a separation as possible of industrial waste gases, which is required evermore urgently today for reasons of environmental protection, it is necessary to produce dust separators by means of which even the finest dust can be removed to a higher degree than in the case of the previous mechanically working separators.
The dust separators well known today have the disadvantage that their degree of separation drops severely as the particle size becomes smaller. Also, the pressure drop caused by the particles is relatively great and a great sweep-gas quantity is required for removal of the dust which involves a considerable energy loss when purifying combustion gases.
These disadvantages are avoided by the dust separator according to the presently claimed invention wherein a main flow conduit conducts the gaseous media. A swirling motion is imparted to the gaseous media within the main conduit. A freely-rotating turbine wheel is arranged at an outlet of the main conduit. The wheel includes blades on the periphery thereof which are acted upon by swirling air from the main conduit to rotate the turbine wheel. An outlet conduit is disposed downstream of said turbine wheel. An annular channel surrounds the turbine wheel. The channel communicates with the main conduit by means of a first gap situated between the outlet of the main conduit and the inlet of the turbine wheel, and communicates with the outlet conduit by means of a second gap situated between the outlet of the turbine wheel and an inlet of the outlet conduit .